PHP 5 in Practice

Computer programming books come in all varieties, but there are at least four general categories: introductory texts, which typically have the lowest content per page; language references, which have become increasingly supplanted by online sources; "advanced" treatments, which are often a mishmash of errata-riddled articles; and "how-to" books, usually at the intermediate level, and sometimes presented as "cookbooks". It is that last category that has been growing in popularity, and for good reason: When an experienced software developer needs assistance, it is rarely for language syntax, but instead a desire to see how someone else solved a specific problem. For solutions using the PHP language, one source of information is PHP 5 in Practice.

The book was authored by Elliott White III and Jonathan D. Eisenhamer, and put out on 21 July 2006 by Sams Publishing (an imprint of Pearson Education), under the ISBN 978-0672328886. Given today's standards of hefty technical books, this particular one is relatively light, weighing in at 456 pages, which are organized into an introduction, numerous chapters, and three appendices.

Its introduction is more interesting than that of most similar books, whose introductions usually consist of formatting conventions and explanations as to why the book was written — all such content providing little to no value to the impatient programmer facing a deadline, and invariably ignored (the content, that is, not the deadline).

White and Eisenhamer took a refreshingly different tack, and chose instead to explain their use of coding standards, comments and whitespace, braces and parentheses, PHP short tags, PHP mode, and other language considerations that are more useful than the typical rundown of somewhat childish icons used in other texts, such as light bulbs and red warning signs.

Switching to the other end of the book, we find three appendices. The first one briefly discusses issues one might face in migrating from PHP version 4 to 5. The second introduces the Standard PHP Library (SPL), and the objects related to its primary design pattern, the Iterator. The third appendix discusses what composes the bulk of output from my PHP programs: error messages. Seriously, this appendix is worth reading, if only for the suggestions as to what to look for when you encounter some of the most common PHP error messages.

The bulk of the book's material is divided into 20 chapters, which are themselves divided into two parts: PHP internals, and applications. The internals are: strings, numbers, time and date, variables, arrays, functions, classes and objects, and files and directories. Starting off with a discussion of strings, might seem odd to the neophyte programmer, but to the veteran who has had to learn several languages during their career, the choice makes a lot of sense. There must be countless developers out there who, being fluent in the C language and object-oriented concepts, jumped into writing their first C++ program, and had to hit the books for the first time when they wanted to do some non-array-based string handling.

The book's second part covers some of the most common applications in PHP programming: Web page creation (using XHTML and CSS), Web form handling, data validation and standardization, sessions and user tracking, Web services and other protocols, relational databases and other data storage methods, e-mail, XML, images, error reporting and debugging, and user authentication and encryption. That last chapter, in the next edition, should be relocated so that it precedes or follows the chapter on sessions and user tracking.

Many of the chapters begin with a "Quick Hits" section, which briefly summarizes how to perform many of the most common and essential tasks related to that chapter's topic. For instance, in the chapter covering the use of variables, this first section explains how to: check if a variable has no value or if it is empty (not synonymous in PHP), undefine a variable, cast it to a certain data type, and do the same thing for a value. There is one minor erratum that should be noted: On page 71, in the first "Quick Hit", it reads "a variable has bee. given a value". ("been"'s "n" ended too soon!)

Each section within the chapter briefly explains the problem domain, and then presents sample code to solve the given problem. The code itself is fairly well commented, and the variable names are adequately descriptive (unlike in some programming books, whose coding standards border on the criminal).

All in all, the book offers a lot of worthwhile solutions to a wide range of problems, and does so in a straightforward manner. It is for this reason that it is not evident as to why this particular PHP title has received so little notice. For instance, on Amazon.com, it has received only one reader review, as of this writing, and does not even make it into the top quarter million books ranked in sales by Amazon.com. It is a pity, because the book deserves much more attention.

Even though this book is to be recommended, and is packed with code and text that are well worth studying, it has one unmistakable weakness for which this writer can think of no adequate justification. The book contains almost no illustrations, even when they are clearly called for — in fact, especially in those cases. For instance, the section that shows how to generate a calendar, does not show a calendar! The code is present, but the sample output — which is what the poor reader would appreciate, to see the results of the code — is missing.

Granted, an absence of figures and screenshots might be understandable for the first part of the book, which covers the PHP language itself. But the second part, covering applications, has far too many unillustrated PHP scripts. These include sections focusing on drop-down menus, progress bars, and graphical charts Web forms. In the last chapter, there is a section with code that generates captchas, but the reader is not shown what they look like. The entire 18th chapter is devoted to images, but contains not a single one! I cannot imagine why the authors and/or publisher chose to leave out these essential graphics. Was it to save money? Whatever the reason, it was a significant mistake, and one that should be corrected in the next edition.

Readers who agree with this assessment, or who have other thoughts concerning this otherwise excellent book, can leave feedback via the book's Web page on the website for Sams Publishing. This page offers details on the book, a description and table of contents, links for requesting instructor or review copies, and a tool for searching the book's contents within the Safari online technical library. The book's introduction states that the website hosts all of the code listings, as well as a list of errata. Yet, I was unable to find either one. (Sadly, the Pearson Education sites are still some of the least usable in the technical book publishing world.) Much better results were obtained on Eli White's site.

Despite an inexcusable and almost complete lack of needed illustrations, PHP 5 in Practice is possibly one of the most meaty, immediately useful, and fluff-free PHP books available. No serious PHP programmer should be without it.